Coiling roll for wire coiling machine



mil:

May 18, 1965 s. A. PLATT 3,183,698

COILING ROLL FOR WIRE COILING MACHINE Filed Jan. 29, 1962 6 INVENTOR.

United States Patent 3,183,698 COILING ROLL FOR WIRE COILING MACHINE Stephen A. Flatt, 1100 Fulton St., Grand Haven, Mich. Filed Jan. 29, 1962, Ser. No. 169,228 6 Claims. (Cl. 72-145) This invention relates to coiling rolls for a wire coiling machine, and more particularly to a coiling roll construction which eliminates dimensional deformation of the wire during the coiling operation.

Wire coiling machines are well-known and usually consist of a pair of rotary heads disposed on opposite sides of a rotating mandrel. As the mandrel and the coiling heads rotate, coiling rolls mounted on the coiling heads engage the wire and bend it around the mandrel to form the coil.

Previously, the discharge of the coil has always been accomplished by squeezing the first wire convolution at the feed end of the coil between the finished portion of the coil and back-up rings mounted on the coiling heads adjacent the coiling rolls. As the wire was squeezed into position, it pushed the coil out of the way and thus advanced the coil toward the discharge end of the coiling rolls, where the finished coil was discharged from the mandrel.

As machines of this type were utilized more and more for precision applications, the reject rate of coils so pro duced became alarmingly greater. Research into the causes of this trouble showed that as the wire was squeezed into place between the finished coil and the back-up ring at the feed end of the coiling rolls, it was subjected to erratic mechanical stresses which caused minute dimensional deformations in the wire. In precision-wound coils, these minute deformations resulted in uneven resistance characteristics and made the coils unsuitable for their intended use. It therefore became evident that in order to produce high precision coils, it would be necessary to feed the wire to the coiling rolls in such a manner as to prevent any lateral stress from being exerted on the wire during the coiling process.

The present invention solves this problem by eliminating the back-up ring and instead providing the coiling rolls with shallow grooves which engage four or five convolutions of wire at one time and push them toward the discharge end of the mandrel without any push from the first convolution. In order to accurately guide the Wire in place on the first convolution, and also in order to distribute the bending stress at the moment of coiling over a longer increment of wire, one or both of the coiling rolls are provided with an annular groove which receives the wire from the feed roll and guides it into place on the mandrel.

It is therefore the object of this invention to provide a coiling roll which does not impose any lateral compressional strain on the wire to be coiled.

It is another object of this invention to provide a coil ing roll in which the bending stress imposed on the wire during the coiling operation is distributed over half a convolution or even over an entire convolution.

These and other objects of the invention will become apparent from the following specification taken in connection with the attached drawings, in which:

FIG. 1 is a schmatic side elevational view of the coiling mechanism of this invention;

FIG. 2 is a plan view of a part of the coiling mechanism of FIG. 1;

FIG. 3 is a partial vertical section through the coiling rolls at the guide grooves to show an alternative embodiment of the invention;

FIG. 4 is a fragmentary plan view, with the coil in horizontal section, of the embodiment of FIG. 3;

FIG. 5 is a view similar to FIG. 4 but showing a third embodiment of the invention; and

FIG. 6 is a view similar to FIG. 4 but showing a fourth embodiment of the invention.

Basically, the invention consists in guiding the feed end convolution of the coil into place on the mandrel and gradually bending it into position, and then advancing the finished coil toward the discharge end of the mandrel by a screw-thread action of the coiling rolls rather than by a pushing action resulting from a squeezing of the feed end convolution into place.

Referring now to FIG. 1, the wire 10 is schematically shown as being unwound from a storage roll 12, drawn through a lubricating bath 14 and directed upwardly toward the coiling roll 16 by a feed roll 18. The wire 10 is received in the guide groove 26 of coiling roll 16 and is partially bent thereby at 22. The bending action is then completed by the coiling roll 24 which bends the wire 10 against the mandrel 26 to complete the forming of the coil. It will be seen that in the embodiment of FIGS. 1 and 2, the bending operation takes place in two in stallments at points 22 and 28, respectively. .After the wire has been fully formed to its coil shape, it is engaged alternately by the shallow grooves 30 of coiling roll 16 and 32 of coiling roll 24. The coaction of grooves 30 and 32 results in transporting the coil 34 in the direction of the arrow in FIG. 2 toward the discharge end of mandrel 26 as the coiling roll, coil and mandrel rotate in the direction of the arrows in FIG. 1.

FIGS. 3 and 4 illustrate an alternative embodiment in which the bending of the wire takes place not at two points 22, 28 as in FIGS. 1 and 2, but at three points 36, 38, and 40. For this purpose, both the coiling roll 16 and the coiling roll 14 are equipped with guide grooves 20 and 42, respectively. As appears more clearly from FIG. 4, the wire 10 is first fed into the guide groove 20 of coiling roll 16, whose depth is approximately twice the diameter of wire 16]. The wire 10 is then bent over into guide groove 42 of coiling roll 24, which is approximately half as deep as groove 20. The second instalhnent of bending occurs when wire 10 engages the bottom of groove 42 at point 38. From point 38, the wire travels around the underside of the mandrel 26 to point 40, where it is engaged by the very shallow groove 44 of coiling roll 16 and is bent against the mandrel 26 into its final shape. The path of wire 10 now continues around mandrel 26 to grooves 46, 48, 50, 52, 54, and 56 in that order. It will be seen that if the various elements of the device rotate in the direction shown in FIG. 1, the grooves 44 through 56 advance the coil 34 downwardly in FIG. 4 along mandrel 26.

FIGS. 5 and 6 illustrate embodiments similar to FIGS. 2 and 4, but modified for the winding of coils in which two parallel wires are wound together. For this purpose, the groove 20 is divided into two parallel grooves 26a and 26b, and (in FIG. 6) the groove 42 is divided into grooves 42a and 42b. In this embodiment, the Wire 1011 is engaged successively by grooves 26a, 42a, 44, 46, and 52, whereas wire 10b is engaged successively by grooves Zilb, 42b, 48 and 50. Otherwise, the action of the devices shown in FIGS. 5 and 6 is the same as the action of devices of FIGS. 2 and 4, respectively.

It will be seen that the present invention provides a simple way of eliminating the lateral compression of the wire during the coiling operation and thus make possible the production of much more precise coils than was heretofore possible. Obviously, the invention can be carried out in many different ways, and it is therefore not desired that the invention be limited by the embodiments shown, but only by the scope of the following claims.

I claim:

1. In a wire coiling machine having a pair of rotatable heads disposed on opposite sides of a mandrel and each e'arrying a coiling roll, the improvement comprising: said coiling rolls having shallow annular grooves formed therein on centers generally equalto the spacing between the centers of adjacent convolutions of the coil to be produced by said machine, and'orie df said rolls having an annular, initial bending and guide groove forniedtherein being the lead groove on said one roll, said guide groove being substantially deeper than said shallow grooves to initiate coil formation and also-feed the coil into such shallow grooves for further coil formation to the final coil form and sustained axial movement ofthe final-coil along the mandrel.

2. Ina wirecoiling machine having a pair of rotatable heads disposed on opposite sides of a' mandrel and each carrying a coiling roll, the improvement comprising: said coiling rolls having shallow annular grooves formedtherein on centers generally equal to the spacing between the centers of adjacent convolutions of the coil to be produced by said machine, and one of said rolls having an annular, initial bending and guide groove formed therein, being the lead groove on said one roll to initially receive the wire, and of a depth approximately twice the depth of said shallow grooves to initiate coil formation and feedtthe coil into said shallow grooves for further coil formation in the final form and sustained axial advancement of the final coil along the mandrel.

3. In a wire coiling machine having a pair of rotatable heads disposed on opposite sides of a mandrel and each carrying a coiling roll, the improvement comprising: said coiling rolls havingshallow annular grooves formed therein on centers generally equal to the spacing between the centers of adjacent convolutions of the coil to be produced by said machine, and one of said rolls having a plurality of adjacent annular guide grooves formed there in on one end of the roll, the number of said guide grooves being equal to thenumber of wires interwound to form said coil, and said guide grooves beingsubstantially deeper than said shallow grooves to initially receive the wires and bend them to initiatecoil formation, and to also feed the coils into said shallow grooves for further coil formation to the final form and sustained'axial advancement of the coil along the mandrel.

4. In a wire coiling machinehaving a pair of rotatableheads disposed on opposite sides of a mandrel and each carrying a coiling roll, the improvement comprising; said coiling rolls having shallow annular grooves formed therein on centers generally equal to the spacing between the centers of adjacent convolutions of the coil to be pro duced by said machine, one of said rolls having a plurality of adjacent annular guide grooves formed therein, being the lead grooves on said one roll, the number of said guide grooves being equal to the number of wires interwound to form said coil, and said guide grooves being substantially deeper than said shallow grooves, to initially receive the wire and start the coil formation, and an equal number of adjacent guide grooves formed in the other of said rolls ofa depth approximately half the depth of said guide grooves in said one of said rolls and at the lead end of said other roll to receive the wires from said guide grooves in said one roll to continue the coil formation and feed the coils into said shallow grooves for further coil formation and coil advancement along said mandrel.

5; In a Wire coiling machine having front and rear rotatable heads disposed on opposite sides of a rotatable mandrel for bendingwire around said mandrel to form a coil, said'heads each carrying front and rear coiling rolls, respectively, and said coil being moved axially of said mandrel during the coiling operation'from the feed end to the discharge end of said rolls, the improvement comprisingza plurality of shallow annular grooves formed in said rolls on centers generally equal to the spacing between the centers of adjacent convolutions of said coil; and an annular guide groove formed in said rear coiling roll at the feed end thereof, said guide groove having a depth of at least the diameter of the wire to be coiled.

V 6. In a wire coiling machine having front and rear rotatable heads disposed on opposite sides of a rotable mandrel for bending wire around said mandrel to form a coil, said heads each carrying front and rear coiling rolls, respectively, and, said coil being moved axially of said mandrel during the coiling operation from the feed end to the discharge end of said rolls, the improvement comprising: shallow annular grooves formed in said rolls on centers generally equal to the spacing between the centers of adjacent convolutions of said coil; and annular guide grooves formed in said front and rear coiling rolls at the feed ends thereof, said groove in said front roll having a depth of at least the diameter of the wire to be coiled, and said guide groove in said rear roll having a depth of at least twice the diameter of the wire to be coiled.

References Eited by the Examiner 1 UNITED STATES PATENTS CHARLES W LANHAM, Primary Examiner. 

1. IN A WIRE COILING MACHINE HAVING A PAIR OF ROTATABLE HEAD DISPOSED ON OPPOSITE SIDES OF A MANDREL AND EACH CARRYING A COILING ROLL, THE IMPROVEMENT COMPRISING: SAID COILING ROLLS HAVING SHALLOW ANNULAR GROOVES FORMED THEREIN ONE CENTERS GENERALLY EQUAL TO THE SPACING BETWEEN THE CENTERS OF ADJACENT CONVOLUTIONS OF THE COIL TO BE PRODUCED BY SAID MACHINE, AND ONE OF SAID ROLLS HAVING AN ANNULAR, INITIAL BENDING AND GUIDE GROOVE FORMED THEREIN BEING THE LEAD GROOVE ON SAID ONE ROLL, SAID GUIDE GROOVE BEING SUBSTANTIALLY DEEPER THAN SAID SHALLOW GROOVES TO INITIATE COIL FORMATION AND ALSO FEED THE COIL INTO SUCH SHALLOW GROOVES FOR FURTHER COIL FORMATION TO THE FINAL COIL FORM AND SUSTAINED AXIAL MOVEMENT OF THE FINAL COIL ALONG THE MANDREL. 